R help - Oct 2008 - how to convert data from long to wide format ?

Given a dataframe m 
> m
   X Y V3 V4
1 1 A 0.5 1.2
2 1 B 0.2 1.4
3 2 A 0.1 0.9  

How do I convert m to this with V4 as the cell values ? 

   A    B
1 1.2 1.4
2 0.9 NA

Try this:

xtabs(V4 ~ X + Y, data = m)



On Thu, Oct 30, 2008 at 9:29 AM, Daren Tan <daren76@hotmail.com> wrote:
>
> Given a dataframe m
> > m
>   X Y V3 V4
> 1 1 A 0.5 1.2
> 2 1 B 0.2 1.4
> 3 2 A 0.1 0.9
>
> How do I convert m to this with V4 as the cell values ?
>
>   A    B
> 1 1.2 1.4
> 2 0.9 NA
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O

	[[alternative HTML version deleted]]

You can look at the reshape package:
> x
  X Y  V3  V4
1 1 A 0.5 1.2
2 1 B 0.2 1.4
3 2 A 0.1 0.9
> z <- melt(x[,-3])  # ignore V3
Using X, Y as id variables
> z
  X Y variable value
1 1 A       V4   1.2
2 1 B       V4   1.4
3 2 A       V4   0.9
> cast(z, X ~ Y, sum)
  X   A   B
1 1 1.2 1.4
2 2 0.9  NA
>

On Thu, Oct 30, 2008 at 7:29 AM, Daren Tan <daren76 at hotmail.com>
wrote:
>
> Given a dataframe m
>> m
>   X Y V3 V4
> 1 1 A 0.5 1.2
> 2 1 B 0.2 1.4
> 3 2 A 0.1 0.9
>
> How do I convert m to this with V4 as the cell values ?
>
>   A    B
> 1 1.2 1.4
> 2 0.9 NA
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?